The invention in a broad aspect relates to a multi-lumen catheter and a method for using the catheter for performing transurethrovesical biopsies, amniocenteses and other biological sampling procedures. More particularly, the invention provides for filling a bladder or other body cavity with a solution to increase sonographic visibility, during sonographic monitoring, and guiding a needle through the bladder or other cavity to accomplish a biopsy, amniocentesis or other biological sampling procedure.
Conventional amniocentesis is performed by passing an amniocentesis needle through the abdominal wall to gain access to the amniotic sac. Care must be exercised when passing the needle to avoid misguidance of the needle resulting in injury to the mother or fetus.
Because X-ray imaging may damage the fetus, the preferred imaging method to aid in guiding the amniocentesis needle is sonographic. Typically, a sonographic transducer is positioned to allow observation of the amniotic sac and the amniocentesis needle as the needle approaches and enters the amniotic sac. When a sonographic image is made through a cavity, the quality of the image, referred to as sonographic visibility, is improved when the cavity is filled with a fluid, preferably a liquid, rather than merely air.
The problems associated with traditional amniocentesis include, but are not limited to, risks of infection resulting if a piece of bowel is inadvertently pierced by the amniocentesis needle or infection resulting from the needle passing through the skin of the mother. A further complication may occur where the mother is significantly overweight producing difficulties in positioning the amniocentesis needle.
Because amniocentesis is currently being performed as early as eight to nine weeks into gestation, high precision in positioning and guiding the amniocentesis needle during insertion and sampling is required to avoid contacting or damaging the small fetus Increased sonographic visibility and a positionable guide for the amniocentesis needle can reduce the risks associated with amniocentesis. Increased visibility and a positionable guide can also reduce risks, such as risk of infection, associated with other biosampling procedures including, but not limited to transurethrovesical biopsies. Biosampling, as used throughout this application, means the obtaining of a biological sample, including but not limited to, a biological sample of an internal organ or a bodily fluid.